The invention is directed to be a hand portable exercise and training machine to improve the user's initial linear quickness and speed from a set or stationary position. This machine is designed to give coaches, trainers, athletes, or bodybuilders at any level a functional, portable alternative to the larger stationary gym based equipment that exploits this same range of functional muscular movement of the legs. It also has a quite positive aesthetic effect on the user's legs. This machine can be used at any stage of periodization: Anatomical Adaptation, Hypertrophy, Maximum strength, Conversion to power, or Maintenance phase. Also, at low resistance it can be utilized in dynamic warm-ups. This machine's function and portability make it a must for any team or individual with a need for speed-development or enhancement.
Endelman et al in U.S. Pat. No. 6,971,976 developed a concept of a movable carriage on a horizontal frame operating against elastic or spring resistance devices. The elastic or spring resistance is applied from the movable carriage to the fixed position, horizontal frame. This Endelman et al exercise machine positions the user in a recumbent, horizontal (laying down) orientation and exercises the user's body trunk and legs in that position. Due to the user position (recumbent instead of upright—standing), the Endelman et al machine is designed to exercise different user muscle groups than those exercised by the machine proposed in this application.
Sleamaker in U.S. Pat. No. 5,328,427 developed a device using movable foot pads connected by cables to a spring loaded one-way clutch driver. The spring loaded one-way clutch driver is also connected by cables to elevated “ski pole” hand grips. The Sleamaker exercise machine positions the user in an upright, standing orientation but the leg movement is restricted to a lateral (sideways) direction. The lateral direction restriction simulates the side ways motion required by ice skating and cross-country skiing. Due to this lateral leg motion direction restriction, the Sleamaker machine is designed to exercise different user leg muscle groups than those exercised by the machine proposed in this application.
Both Endelman et al and Sleamaker employ standard engineering techniques such as telescoping, removable or collapsing features to enhance the portability or storability of their exercise equipment. The machine proposed in this application also employs telescoping and removable features to enhance the portability or storability.
The key to successful linear sprinting is a powerful and technically sound initial drive phase which comprises the first six to eight steps of a sprint. The first step out of the blocks requires the runner to achieve triple extension of the hip, knee, and ankle joints. Then the runner must hold a 45 degree angle from toe off to head, in order to place maximum force into the ground, this angle trains the “acceleration vector.” This first six to eight steps is not easy to train or develop. So by putting the runner in the start position per the machine defined in this application, the runner can then work the first step against the resistance of the springs to full extension of the hip, knee, and ankle and gain maximal range of motion strength.
The acceleration vector mentioned above, comes from load vector terminology, which can be used to clarify the differences between Endelman's reformer exercise apparatus which trains the jump vector, Sleamaker's skating and skiing simulator, which trains the cutting vector. Whereas, the machine proposed in this application trains the acceleration vector.
In order to understand load vector training terminology, you simply need to analyze which direction the load is moving in relation to the human body. Muscular activation is directly correlated to the directional load vector. The primary load vectors can be defined as follows:                Sprint Vector: Characteristic of top speed sprinting with upright posture, moves weight forward and backward in relation to the upright human body        Acceleration Vector: Characteristic of forward acceleration with 45 degree lean, halfway between sprint vector and jump vector        Jump Vector: Characteristic of jumping, moves weight up and down in relation to upright human body        Backpedal Vector: Characteristic of backpedaling or moving backwards        Cutting Vector: Characteristic of lateral cutting and sideways movements        Twisting Vector: Characteristic of twisting or rotating motions        
Athletes need to prepare for all the vectors related to their sport. It is very difficult to keep things simple and train all the various load vectors. Usually, the jump vector is heavily loaded in the weight room and the other vectors are trained with bodyweight only on the field through speed and agility training. Training more vectors in the athlete's strength program will maximize performance and reduce injuries. The machine defined in this application is targeted to train both a movement and its associated muscles. The targeted movement being trained is the acceleration vector as defined above.
In summary, the Endelman et al and Sleamaker exercise machines' are designed to exercise very different user muscle groups than those exercised by the machine proposed in this application. The Endelman et al and Sleamaker designs position the user in different body orientations and the user's motions when using these devices are very different than the machine proposed in this application. The machine proposed in this application is primarily targeted at leg muscles used to initiated and maintain forward motion as employed during running or walking and during the initiation of those activities. Again, the user orientation and exercise motions for the machine proposed in this application are very different than either the Endelman et al or Sleamaker exercise machines.